Method of bonding a poly (vinylidene fluoride) solid to a solid substrate

Abstract

The invention deals with a method of bonding a poly(vinylidene fluoride) solid to a variety of solid substrates, in an application typically using the piezoelectric properties of the material. The bonding method entails surface preparation of the poly(vinylidene fluoride) by a variety of steps including activation of the surface by plasma etching to cause the surface to wet the adhesive used in the bonding process. The bonding method produces bonds of increased strength and having good electrical properties.

What is claimed is: 
     
       1. The method of preparing a poly(vinylidene fluoride) (PVF 2 ) solid for bonding to a solid substrate comprising the steps of: A. providing a PVF 2  solid containing crystallites, (1) abrading the surface of the PVF 2  solid to provide an irregular bonding surface,   (2) rinsing the surface of the PVF 2  solid to remove surface contaminants,   (3) plasma etching the surface of the PVF 2  solid to create a temporary high energy bonding surface by activated free radical and ionic species of oxygen, while keeping the PVF 2  solid at a temperature below the melting point of its crystallites for dimensional stability, and   (4) applying a primer to the surface of the PVF 2  solid capable of wetting the activated high energy surface of the PVF 2 , before the temporary high energy bonding surface has deteriorated.     
     
     
       2. The method of claim 1 wherein: said PVF 2  contains polarized, oriented crystallites, and wherein:   the temperature of the PVF 2  solid, during plasma etching is kept below that for reversion to the unpolarized state.   
     
     
       3. The method of bonding a poly(vinylidene fluoride) (PVF 2 ) solid to a solid substrate comprising the steps of: A. providing a PVF 2  solid containing crystallites, (1) abrading the surface of the PVF 2  solid to provide an irregular bonding surface,   (2) rinsing the surface of the PVF 2  solid to remove surface contaminants, and   (3) plasma etching the surface of the PVF 2  solid by activated free radical and ionic species of oxygen, while keeping the PVF 2  solid at a temperature below the melting point of its crystallites for dimensional stability;     B. providing a solid substrate, (1) abrading the surface of the substrate to provide an irregular bonding surface,   (2) rinsing the surface of the substrate to remove surface contaminants, and     C. attaching the PVF 2  solid to the substrate before the temporary high energy bonding surface has deteriorated by use of an adhesive adherent to the prepared surface of the substrate and capable of wetting the activated high energy PVF 2  surface.   
     
     
       4. The method of claim 3 wherein: said PVF 2  solid contains polarized, oriented crystallites, and wherein   the temperature of the PVF 2  solid, during plasma etching, is kept below that for the reversion to the unpolarized state.   
     
     
       5. The method of bonding a poly(vinylidene fluoride) (PVF 2 ) solid to a metallic substrate comprising the steps of: A. providing a PVF 2  solid containing crystallites, (1) abrading the surface of the PVF 2  solid to provide an irregular bonding surface,   (2) rinsing the surface of the PVF 2  solid to remove surface contaminants, and   (3) plasma etching the surface of the PVF 2  solid to create a temporary high energy bonding surface by activated free radical and ionic species of oxygen, while keeping the PVF 2  solid at a temperature below the melting point of its crystallites for dimensional stability;     B. providing a metallic substrate, (1) abrading the surface of the substrate to provide an irregular bonding surface,   (2) rinsing the surface of the substrate to remove surface contaminants, and   (3) applying a coupling agent to the surface of the substrate with organic and inorganic constituents having an organic to an inorganic coupling affinity; and     C. attaching the PVF 2  solid to the substrate by use of an adhesive adherent to the prepared surface of the substrate and capable of wetting the high energy organic surface before the temporary high energy bonding surface has deteriorated.   
     
     
       6. The method of claim 5 wherein: said PVF 2  solid contains polarized, oriented crystallites, and wherein:   the temperature of the PVF 2  during plasma etching is kept below that for reversion to the unpolarized state.   
     
     
       7. The method of bonding a poly(vinylidene fluoride) (PVF 2 ) solid to a metallic substrate comprising the steps of: A. providing a PVF 2  solid containing crystallites, (1) abrading the surface of the PVF 2  solid to provide an irregular bonding surface,   (2) rinsing the surface of the PVF 2  solid to remove surface contaminants,   (3) plasma etching the surface of the PVF 2  solid to create a temporary high energy bonding surface by activated free radical and ionic species of oxygen, while keeping the PVF 2  solid at a temperature below the melting point of its crystallites for dimensional stability,   (4) applying a primer to the plasma etched surface of the PVF 2  solid before the temporary high energy bonding surface has deteriorated, capable of wetting the activated high energy PVF 2  surface,     B. providing a metallic substrate, (1) abrading the surface of the substrate to provide an irregular bonding surface,   (2) rinsing the surface of the substrate to remove surface contaminants,   (3) applying a coupling agent to the surface of the substrate having an organic to organic coupling affinity; and     C. attaching the PVF 2  solid to the substrate by use of an adhesive having an organic to organic coupling affinity for adhesion between said primer and coupling agent.   
     
     
       8. The method of claim 7 wherein: said PVF 2  solid contains polarized, oriented crystallites, and wherein:   the temperature of the PVF 2  during plasma etching is kept below that for reversion to the unpolarized state.   
     
     
       9. The method of bonding a poly(vinylidene fluoride) (PVF 2 ) solid to a solid organic substrate comprising the steps of: A. providing a PVF 2  solid containing crystallites, (1) abrading the surface of the PVF 2  solid to provide an irregular bonding surface,   (2) rinsing the surface of the PVF 2  solid to remove surface contaminants, and   (3) plasma etching the surface of the PVF 2  solid to create a temporary high energy bonding surface by activated free radical and ionic species of oxygen, while keeping the PVF 2  solid at a temperature below the melting point of its crystallites for dimensional stability,     B. providing a solid organic substrate, (1) abrading the surface of the substrate to provide an irregular bonding surface,   (2) rinsing the surface of the substrate to remove surface contaminants, and     C. attaching the PVF 2  solid to the substrate before the temporary high energy bonding surface has deteriorated by use of an adhesive capable of wetting the activated high energy PVF 2  surface.   
     
     
       10. The method of claim 9 wherein: said PVF 2  solid contains polarized, oriented crystallites, and wherein:   the temperature of the PVF 2  solid, during plasma etching, is kept below that for reversion to the unpolarized state.   
     
     
       11. The method of bonding a poly(vinylidene fluoride) (PVF 2 ) solid to a solid organic substrate comprising the steps of: A. providing a PVF 2  solid containing crystallites, (1) abrading the surface of the PVF 2  solid to provide an irregular bonding surface,   (2) rinsing the surface of the PVF 2  solid to remove surface contaminants,   (3) plasma etching the surface of the PVF 2  solid to create a temporary high energy bonding surface by activated free radical and ionic species of oxygen, while keeping the PVF 2  solid at a temperature below the melting point of its crystallites for dimensional stability, and   (4) applying a primer to the plasma etched surface of the PVF 2  solid before the temporary high energy bonding surface has deteriorated, capable of wetting the activated high energy PVF 2  surface,     B. providing a solid organic substrate, (1) abrading the surface of the substrate to provide an irregular bonding surface,   (2) rinsing the surface of the substrate to remove surface contaminants, and     C. attaching the solid PVF 2  layer to the organic substrate by use of an adhesive having an organic to organic coupling affinity.   
     
     
       12. The method of claim 11 wherein: said PVF 2  solid contains polarized, oriented crystallites, and wherein:   the temperature of the PVF 2  solid, during plasma etching, is kept below that for reversion to the unpolarized state.   
     
     
       13. The method of bonding a poly(vinylidene fluoride) (PVF 2 ) solid to an aluminum substrate comprising the steps of: A. providing a PVF 2  solid, (1) abrading the surface of the PVF 2  solid to provide an irregular bonding surface,   (2) rinsing the surface of the PVF 2  solid to remove surface contaminants,   (3) plasma etching the surface of the PVF 2  solid to create a temporary high energy bonding surface by activated free radical and ionic species of oxygen, while keeping the PVF 2  solid at a temperature below the melting point of its crystallites for dimensional stability,     B. providing an aluminum substrate, (1) abrading the surface of the aluminum substrate to provide an irregular bonding surface,   (2) rinsing the surface of the aluminum substrate to remove surface contaminants, and   (3) acid etching the surface of the aluminum substrate to provide an irregular bonding surface at the metallic grain scale and to remove excess oxide, and     C. attaching the PVF 2  solid to the substrate before the temporary high energy bonding surface has deteriorated by use of an adhesive adherent to the prepared surface of the substrate, and capable of wetting the activated high energy PVF 2  surface.   
     
     
       14. The method of claim 13 wherein: said PVF 2  solid contains polarized, oriented crystallites, and wherein:   the temperature of the PVF 2  solid, during plasma etching, is kept below that for reversion to the unpolarized state.   
     
     
       15. The method of bonding a poly(vinylidene fluoride) (PVF 2 ) solid to an aluminum substrate comprising the steps of: A. providing a PVF 2  solid, (1) abrading the surface of the PVF 2  solid to provide an irregular bonding surface,   (2) rinsing the surface of the PVF 2  solid to remove surface contaminants,   (3) plasma etching the surface of the PVF 2   solid to create a temporary high energy bonding surface by activated free radical and ionic species of oxygen, while keeping the PVF 2  solid at a temperature below the melting point of its crystallites for dimensional stability,     B. providing an aluminum substrate, (1) abrading the surface of the substrate to provide an irregular bonding surface,   (2) rinsing the surface of the substrate to remove surface contaminants, and     C. attaching the solid PVF 2  layer to the aluminum substrate by use of an epoxy adhesive.   
     
     
       16. The method of claim 15 wherein: said PVF 2  solid contains polarized, oriented crystallites, and wherein:   the temperature of the PVF 2  solid, during plasma etching, is kept below that for reversion to the unpolarized state.